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Cystometry

Test Overview

Cystometry is a test that measures the pressure inside of the
bladder to see how well the bladder is working.
Cystometry is done when a muscle or nerve problem may be causing problems with
how well the bladder holds or releases urine.

Urination is a
complex process. As the bladder fills, nerves in the bladder wall send a
message to the
spinal cord and brain that you need to urinate. In response, your spinal cord
sends a signal for the bladder to contract (voiding reflex). When you hold in
your urine, your brain is overriding this reflex. When you allow the reflex to
occur, urination occurs. A problem affecting this nerve pathway or the muscles
of the bladder wall can cause bladder dysfunction.

During
cystometry, your bladder is filled with water or gas to measure its ability to
hold in and push out the water or gas. Medicine may also be given to see
whether your bladder contracts or relaxes normally in response to the medicine.
A small tube (catheter) can be placed in your
rectum to measure pressure as the bladder fills. A
small pad or needle may be placed near your
anus to measure muscle function in this area.

Why It Is Done

Cystometry is done to:

Find the cause of problems with the
bladder or the muscle that holds urine in the bladder
(bladder sphincter). Problems in one or both of these areas may cause
uncontrolled urine leakage, an urgent feeling that you have to urinate, or a
weak urine stream.

Measure how much urine your bladder can store and how much urine
remains in your bladder after you feel you have completely emptied it (residual
volume).

Help you and your doctor make decisions about how to treat your
urinary symptoms.

See how well the bladder works in people with
progressive neurological diseases, such as
multiple sclerosis.

How To Prepare

Tell your doctor if you:

Are taking any medicines. Some medicines and herbal supplements
can affect bladder function.

Are or might be pregnant.

Have symptoms of a
urinary tract infection, such as pain or burning with
urination, foul-smelling or cloudy urine, or an urge to urinate more often than
usual.

Talk to your doctor about any concerns you have regarding
the need for the test, its risks, how it will be done, or what the results will
mean. To help you understand the importance of this test, fill out the
medical test information form(What is a PDF document?).

How It Is Done

Cystometry is done in a doctor's
office or hospital urology department by a
urologist,
gynecologist, or other trained health
professional.

You will need to take off most of your clothes below
the waist. You will be given a cloth or paper covering to use during the
test.

At the beginning of the test, you will be asked to urinate into a
toilet that is connected to a machine called a uroflowmeter. This machine
measures how much urine passes and how long it takes. The time and effort
needed to start the flow of urine, the number of times you start and stop the
flow of urine, and the presence of dribbling near the end of urinating are also
recorded.

Next, you will be asked to lie on your back on an examining
table. After the
urethra is thoroughly cleaned, a well-lubricated thin,
flexible tube (catheter) is gently inserted and slowly moved into
your bladder. Any urine remaining in your bladder (residual volume) will be
drained and measured.

Next, a catheter is used to fill your bladder with sterile,
room-temperature water. The catheter is also attached to a device called a
cystometer, which measures how much your bladder can hold and the pressure in
your bladder. You will be asked to report any feelings such as warmth, bladder
fullness, or an urge to urinate. The process may be repeated.

Another catheter may be placed in your rectum to
measure the pressure in your abdomen as your bladder fills. A small pad or
needle may be placed near your anus to measure muscle function in this
area.

Each time your bladder is filled, you will be asked to report
when you first feel the urge to urinate. Your bladder will then continue to be
filled until you report that you feel you must urinate. Then the catheter will
be used to drain the bladder, or you will be asked to urinate.

After all the liquid is drained out of your bladder, and if no
additional tests are required, the catheter is removed.

While the catheter is in place, other tests may also be
done to help find out whether the nerves that control urination are working
properly. These include:

Ice water test. Ice-cold water is injected through the catheter into your
bladder.

Bethanechol sensitivity test. Bethanechol is a medicine that normally makes the bladder muscles
contract. In this test, bethanechol will be injected under your skin.

Bulbocavernosus reflex test. To test nerve function, a gloved finger is inserted into your
rectum and then the penis or clitoris is gently squeezed.

Saddle sensation test. The skin around your anus is stroked or lightly pricked with a
pin.

Maximum urethral closure pressure (MUCP). Urethral pressure is recorded as the catheter is gently pulled
out of your urethra. This test helps determine whether the muscles around the
bladder and urethra are functioning properly.

Leak point pressure (LPP). Approximately
200 mL (7 fl oz) of sterile
water is injected into the catheter in your bladder, and then the pressures are
measured while you bear down (as if having a bowel movement). This test helps
find out whether the muscles around the bladder and urethra are working
properly. A low pressure reading may mean that poor muscle function is causing
urinary incontinence.

Another test that may be done is the
stress incontinence test. In this test, your bladder
is filled with water and the catheter is withdrawn. You are then asked to
cough, bend over, or lift a heavy object. Dribbling urine means stress
incontinence.

Cystometry testing usually takes 30 to 60 minutes,
but it may take slightly longer if any of the special tests are done.

After cystometry, you will need to keep track of how much you drink and
how much you urinate for the next 24 hours. A burning sensation during
urination is a common but temporary side effect. Drinking lots of fluids will
help relieve this sensation. You may be given an
antibiotic to help prevent a urinary tract infection.

How It Feels

You may feel embarrassed at having to
urinate in front of other people. This procedure is
quite routine for the medical staff. If you find yourself feeling embarrassed,
take deep, slow breaths and try to relax.

You will feel a strong
urge to urinate at times during the test. You may also find it somewhat
uncomfortable when the catheter is inserted and left in place, and you may be
sore afterward. If so, soaking in a warm tub bath may help.

Risks

Cystometry usually does not cause problems.
There is always a slight risk of developing a urinary tract infection when a
catheter is inserted into the bladder. In rare cases, a bladder infection can
spread to a kidney and into the blood, leading to a life-threatening infection.
If an infection occurs, it can be treated with antibiotics.

If you
have a high spinal cord injury, you may have low heart rate, high blood
pressure, headache, and feel flushed or sweaty during the test. Report these
symptoms to the health professional conducting the test, since further testing
may cause complications.

After the test

After the test, you may need to urinate frequently, with some burning during and after urination for a day or two (especially if carbon dioxide gas was used). Drink lots of fluids to help minimize the burning and to prevent a urinary tract infection.

A pinkish tinge to the urine is common for several days after cystometry. But call your doctor immediately if:

Your urine remains red or you see blood clots after you have urinated several times.

You have not been able to urinate 8 hours after the test.

You have a fever, chills, or severe pain in your flank or abdomen. These may be signs of a kidney infection.

You have symptoms of a urinary tract infection. These symptoms include:

Pain or burning upon urination.

An urge to urinate frequently, but usually passing only small quantities of urine.

Dribbling or leakage of urine.

Urine that is reddish or pinkish, foul-smelling, or cloudy.

Pain or a feeling of heaviness in the lower abdomen.

Results

Cystometry is a test that measures the
pressure inside of the
bladder to see how well the bladder is working.

Some results may be available right away. Full results are usually
available in 1 to 2 days.

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